As a filter to separate a specific gas or liquid from a mixture of a plurality of kinds of gases or liquids, a porous body having a separation membrane formed on its surface is known. Formation of this separation membrane is made by applying a solution containing a precursor to the separation membrane onto a surface of a porous body for forming the separation membrane thereon, thus forming a coating membrane (membrane formation), and followed by performing drying and heat-treatment on thus obtained coating membrane.
Manufacturing a printed wiring circuit board includes the step of forming a resist film having a uniform thickness on a surface of the board, which is done by applying a resist solution onto the surface of the board.
As a method of applying a liquid for forming a membrane (application liquid) onto a surface of a certain object (object to be coated) in manufacturing an article with a membrane having various functions formed on its surface, a dip method has been widely used so far. This method is done, for example as described in Patent Documents 1 to 3, by procedures in which an object to be coated is immersed in an application liquid filled in a vessel (dipping tank), and then the object to be coated is pulled out from the application liquid after a certain time.
However, when a volume or a weight of the object to be coated is large or heavy, the conventional applying method like this requires a large equipment for raising and lowering of the object to be coated associated with its immersion and pull-out, which also makes it difficult to secure a safety in transfer task. When coating membranes are intended to be formed simultaneously on a plurality of objects to be coated, each object to be coated must be raised and lowered with each of them being supported. Further, when a coating membrane is intended to be formed only on a part of a surface of the object to be coated, an entire part other than that part needs to be covered by a sealing material before the object to be coated is immersed in an application liquid, which is laborious.
Patent Document 1: JP-A-2007-38210
Patent Document 2: JP-B-3652053
Patent Document 3: JP-A-5-67861